Perhaps you should try some spelling variations:
toc sach » hoc sach, thuoc sach, nuoc sach
cham luc » cham soc, nhan luc, cham cuu
doc sach » hoc sach, nuoc sach, dac sac
va nang » van nang, da nang, kha nang
hieu va » lieu va, hieu qua
va cham » va chat, va tham
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
cua tre » cua te, cuu tre, cua triet
luc va » duc va, tuc va, loc va
di cua » dai cua, doi cua, de cua

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((toc sach) OR (doc sach)) ((va nang) OR (cam nang)) xa hoi. hieu va cham luc va hanh di cua tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((toc sach) or (doc sach)) ((va nang) OR (cam nang)) xa hoi. hieu va cham luc va hanh di cua tre~".
• Adding a wildcard symbol may retrieve word variants: ((toc sach) or (doc sach)) ((va nang) OR (cam nang)) xa hoi. hieu va cham luc va hanh di cua tre*.